Rising sea levels threaten agriculture

Sudhir Koiborto Das, a 60-year-old local farmer with two hectares of land, was doing well by Bangladeshi standards, but brackish sea water is now encroaching on his farm, rendering it useless.

"The result has been disastrous. The once fertile land of this whole southwestern region has now turned into a huge saline swamp where no vegetation grows," he said.

"The seepage has destroyed the fertility of our crop lands. We cannot grow rice or any vegetables. Coconut palms and banana groves are dying. The coconut water that used to be so sweet and refreshing even a decade ago has now become bitter," he said.

Climate change

Rising sea levels in the Bay of Bengal are encroaching on vast flat agricultural lands in the southern districts of Khulna, Satkhira, Bagerhat, Jessore and Magura - resulting in soil salinity and other environmental hazards.

The once fertile land of this whole southwestern region has now turned into a huge saline swamp where no vegetation grows.

According to the Intergovernmental Panel on Climate Change, Bangladesh is slated to lose the largest amount of cultivated land globally due to rising sea levels. A 1m rise in sea levels would inundate 20 percent of the country’s landmass.

"It is clear that climate change is taking its toll in the form of saline water intrusion into the mainland of Bangladesh, which is one of the lowest-altitude countries in the world," Golam Mohammad Panaullah, a soil scientist and former director of research of the Bangladesh Rice Research Institute (BRRI), told IRIN in Dhaka, the capital.

"In 1973, 1.5 million hectares of land had mild salinity. In 1997, this expanded to 2.5 million hectares," he said.

And while there has yet to be an up-to-date survey, he believed that figure to be more than three million hectares of agricultural land now. Of 37 million people living in 12 coastal districts, 20 million had been affected by the expanding sea, he added.

A soil survey by six government agencies, including the BRRI and the Bangladesh Agricultural Research Council, found higher-than-acceptable soil salinity in 72 percent of all arable land of Magura district, about 200km from the sea.

Since 1948, salinity in the rivers of southern Patuakhali, Pirojpur, Boguna, Satkhira, Bagerhat and Khulna districts has risen by 45 percent.

People use bamboo bridges to cross saline puddles in areas where rising sea water invades villages

Ramifications

According to Panaullah, increased salinity in turn affects soil fertility. On more than 25,000 hectares of land in the south, agricultural production has dropped significantly in recent years. Most of the affected area is less than 1.5m above sea level. With every rising tide, sea water deposits salt on the land.

Cultivation of rice, a food staple, has suffered most, while the production of wheat, pulses, rape seed and coconut has also been affected.

And despite the fact that there is no official record of reduced agricultural output due to increased salinity in the soil, analysts say the drop could be as much as 50 percent over the past 30 years.

Another factor is the sharp rise in shrimp cultivation, which has created permanent saline water-logging in the region.

Shrimp, which need sea water to grow, are a significant foreign-exchange earner and farmers have taken to building high mud walls around their farms to retain the saline sea water of the high tide. Over the past three decades, thousands of shrimp farms have sprung up in the region.

It is clear that climate change is taking its toll in the form of saline water intrusion into the mainland of Bangladesh, which is one of the lowest-altitude countries in the world.

Yet while sea water helps the shrimp farmers, it destroys all other vegetation.

Third, fresh water flow has dropped off significantly in the Padma (Bangladesh branch of the Ganges) since India commissioned the Farakka Barrage upstream. During the dry season (December-June) the Padma flows at less than a quarter of its capacity.

Finally, Panaullah said the stagnant saline water on the surface often seeps into the groundwater - rendering it useless for either irrigation or drinking purposes.

Official line

Golam Hossain, deputy director of the agricultural department, told IRIN that a quarter of all agricultural land in 10 sub-districts in Khulna had been affected by rising sea water.

But while accepting that an incursion of sea water into traditional croplands had reduced crop patterns in the region, Hossain did not believe it was all bad - a sentiment underscoring the government’s reluctance to address the issue or provide any meaningful form of mitigation.

“Farmers are more than compensated for their crop losses by growing shrimp in their erstwhile paddy fields. Shrimp fetches more money than rice,” the government official said.

Niladri Das, a farmer of Da Kope village, whose half-acre of once fertile land has turned into a virtual salt bed due to seepage from shrimp farms, however, disagrees.

“Only a handful of big landowners and the powerful are making money from shrimp. Poor people like us who refuse to sell their land to shrimp farmers are victims of increasing salinity. Some people export shrimp and get filthy rich, but tens of thousands like me are ending up as paupers,” Das complained.

Shafiqul Islam, president of the Water Committee, an advocacy group, said plants are dying while various forms of local fish and livestock now faced extinction, adding that job opportunities had also been reduced and poverty increased in the region.